2 * Various fixed-point math operations
4 * Copyright (c) 2008 Vladimir Voroshilov
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #ifndef AVCODEC_CELP_MATH_H
24 #define AVCODEC_CELP_MATH_H
28 typedef struct CELPMContext
{
30 * Return the dot product.
31 * @param a input data array
32 * @param b input data array
33 * @param length number of elements
35 * @return dot product = sum of elementwise products
37 float (*dot_productf
)(const float* a
, const float* b
, int length
);
42 * Initialize CELPMContext.
44 void ff_celp_math_init(CELPMContext
*c
);
45 void ff_celp_math_init_mips(CELPMContext
*c
);
48 * fixed-point implementation of exp2(x) in [0; 1] domain.
49 * @param power argument to exp2, 0 <= power <= 0x7fff
51 * @return value of (1<<20) * exp2(power / (1<<15))
52 * 0x8000c <= result <= 0xfffea
54 int ff_exp2(uint16_t power
);
58 * @param value function argument, 0 < value <= 7fff ffff
60 * @return value of (1<<15) * log2(value)
62 int ff_log2_q15(uint32_t value
);
65 * Shift value left or right depending on sign of offset parameter.
66 * @param value value to shift
67 * @param offset shift offset
69 * @return value << offset, if offset>=0; value >> -offset - otherwise
71 static inline int bidir_sal(int value
, int offset
)
73 if(offset
< 0) return value
>> -offset
;
74 else return value
<< offset
;
78 * returns the dot product of 2 int16_t vectors.
79 * @param a input data array
80 * @param b input data array
81 * @param length number of elements
83 * @return dot product = sum of elementwise products
85 int64_t ff_dot_product(const int16_t *a
, const int16_t *b
, int length
);
88 * Return the dot product.
89 * @param a input data array
90 * @param b input data array
91 * @param length number of elements
93 * @return dot product = sum of elementwise products
95 float ff_dot_productf(const float* a
, const float* b
, int length
);
97 #endif /* AVCODEC_CELP_MATH_H */